Engine "knock" or "detonations" in an internal-combustion engine are caused by uncontrolled and rapid combustion in the combustion chamber leading to the undesirable generation of heat and pressure; this is attributable to variations in the octane of available fuel, and the prospect is for greater knocking as octane ratings reduce. Knock, when severe, causes a loss of engine efficiency and can cause severe engine damage, such as pitting, cracking or even destruction of the pistons or of the walls surrounding the combustion chamber. This problem is particularly severe with two-cycle engines and when such engines are used in a marine environment, the consequences of engine damage can be catastrophic.
It is, therefore, an object of the instant invention to prevent unnecessary engine damage by reducing, or eliminating, engine knock.
It is a specific object of the instant invention to reduce or eliminate knock with an inexpensive and uncomplicated electronic circuit readily adaptable for use with two-cycle engines.
Various knock-control circuits are known for use with internal-combustion engines, which circuits attempt to control knock merely by adjustment of the spark timing. However, known spark-control circuits cause exhaust-gas temperatures to rise, resulting in development of additional heat in the combustion chamber. Such added heat is undesirable, as it can result in additional or more severe engine damage.
It is, therefore, a still further object of the instant invention to reduce, or eliminate, knock in an internal combustion engine, by means which will reduce heat development in the combustion chamber.